Venting device for liquid and vapor apparatus



Dec. 15, 1931. T. s. DERR 8 7,0 3

VENTING DEVICE FOR LIQUID AND VAPOR APPARATUS Filed March 2, 1925 INVENTORS ATTORNEY I Patented Dec. 15, 1931 PATENT o ,FVICE. 1

THOMAS s. mian, or BROOKLINE, MASSACHUSETTS, ASSIGNOR TO THE] BRISTOL COM- PANY, or WATEBBURY, CONNECTICUT, Aconroaarron or CONNECTICUT VENT'ING DEVICE FOR LIQUTD AND VAPOR APPARATUS Application filed March 2, 1925. Serial No. 12,802.

5 tion with the determination or automatic maintenance of the Water levelof a steam boiler. Apparatus for such maintenance and determination is set forth in U. S- Patent No. 1,357,850, granted to me on the 2nd day of November, 1920, and wherein thermoelectric couples are disclosed as one means for effecting the desiredresult, although it is to be understood that the present invention is not to be restrictedto the use of such measuring or control devices, and any suitable means responding to a difi'erence in temperature existing, for example, between a water column and a contiguous column of steammay be employed.

In connection with the particular embodiment aforesaid, it will be appreciated that the same will afford accurate and reliable indications so long only as the column of steam is maintained contiguous to the varying column of water. In other words, should the steam column be replaced by or become mixed with non-condensible gases, as .mayresult from the condensation of steam in the system, the temperature relationship between steam and water would be disturbed and the measuring system or control would no longer function correctly.

It is the object of the present invention to provide novel venting means whereby to prevent such replacement or mixture from occurring and particularly thru the provision of means whereby any non-condensible gases accumulating in the system will first be conducted to a point more or less remote from the region of measurement and then vented frplm the system eithermanually or automatica y. V

The nature of the invention, however, will best be understood when described in connection with the accompanying drawings, in which I Fig. 1 is an elevation showing the general arrangement of apparatus, with a portion of the protective casing and supplementary water column being broken away.

Fig. 2 is a detail elevation of an automatic venting valve, with portion of the casing broken away to disclose the interior.

Fig. 3 is a detail vertical section of the valve mechanism and outlet.

Referring to the drawings, 10 designates a suitable container for a liquid, for example, in connection with the particular embodiment herein set forth, a supplementary gauge or Water level column which is intended to be connected at the top and bottom in the usual manner, as thru suitable pipes 11 and 12, with a boiler (not shown). This colunm may be surrounded by a suitable protective casing. 13, if desired. Similarly to the arrangement disclosed in the aforesaid patent, the container 10 for the water column is designed to have associated therewith a temperature responsive device 14 which may be connected to'various measuring instruments as the indicating and recording devices 15. The arrangement thus far described is similar to that" set forth in my said prior patent; but it has been found that in the use thereof unless the container 10 be periodically'blown off, as thru a blow-off valve 16, the indicationsof the measuring apparatus will become erratic due to the accumulation of non-condensible gases at one or more'points along the column and which gases are naturally at a different temperature from that of the steam constituting one of the measuring media. However, a blow-ofi' valve is manually controlled and its periodical operation therefore not dependable. It has also been found that the provision of ordinary automatic air venting means in direct connection with the column would not operate satisfactorily in practice, especially with temperatures ob-- taining. at steam per square inch.

It has been found'necessary, therefore, to provide means for first conducting the noncondensible gases away from the column itself before effecting the venting thereof. In accordance with the present invention, this is accomplished by providing a vent pipe 20 which communicates with the container or column, as by extending along the length of the said water column to near thebottom pressures as high as 250 lbs;

gases from within the valve body. Moreover,

in-order to insure the collection and delivery ofthe gasesto said'valve body, atvarying liquid levels as in accommodating fluctuations in level of the water, .thepipe isperforated.

at various points along its length, as shown, to pick up the gases as they may accumulate along said column. Furthermore, it is preferable to construct the valve 22iwith proportionately large ra'diatingsurface, as it has been found desirable to cause condensation ofany steam: occupying: space therein, the Water of condensation trickling bac-k thru the tube 20' and absorbing small. amounts of non condensible gases in: its passage: downwardlya.

An especially suitable type of valve is shown in'Figs. 2 andi3of the drawings, the ordinary type being. unsatisfactory in. view, among other reasons, of the comparatively high: temperatures and pressures employed: No claim, however,.is made'herein to this specific type of valve. shown,.the valve consists of'a body 25'which is connected at one endito' thetube'QO thru an elbow 26 and a connecting" pipe 27 of required length"; The valve body. is of the T typeandmeceives in its top opening an: extension piece 28 closed by a plug-29; 'Ilhe' latterhas' soldered or otherwise secured: thereto: a. thermostatic element'- as a bi-metallic actuating strip; or moving'element 30 which, as is'welliund'em stood, will be aflected by differences oftemperatnre to provide a. slight movement" sub"- stantially at: right angles to" its length. At its outer andifree'end, this strip isaadj ustably secured to a valvc stem" 31? as bybeingrmounte ed between suitable nuts 30 and 30 work ingthereon; saidv stem: being: mounted sub stantially co-axia lly with the horizontall axis of the valve 32: The latter is designed to fit in a valve seat or cavity"33' provided in-a plug 34! closing the end! of the valve: body opposite its elbow connection end; The plug; however, is 'bored: axially thru ;1 the opening passing also thruz the valve seat 33;: and the said stemisp-rovided' with an' extension 35: beyond the ball' valve portion, which. extension fits thru the bore of the plug'with. a slight clearance provided therebctaveen. Movement of tlie-v-alve stem, due to-the' influenceof temperature variations upon the strip, will thus cause the ballitoseat or unseat itselfin the valve seat 33 to seal' or open respectively the outlet thru the plug 34". At the same time, thereciprocat'ory movement of the extension 35 will serve to: keep: this opening "clear at all times-insur-ing theventing of the gases from the valve, and which will occur until steam reaches the bi-metallic strip to cause thereby the same to close the valve at its seat 33. In the provision of the extension piece 35, furthermore, a ready means is afforded for indicating by the amount projecting whether the valve is sealed or open; and external control is afforded thereby, as by pressing inwardly thereon so that the valve may at any time'be caused to open.

In the foregoing apparatus, any gases tending to collect or collecting in the containenlOwillbe picked up thru the perforations of the tube 20 and conducted thru the latter to-the valve 22 from which the same are released untilthe steam again closes this valve. Thereby, the column is suitably vented and thus maintained at all times in proper condition for effecting measurement or control thru the variation in level of liquid therein, when this is contemplated.

It will be appreciated, for example, in water columns attached to steam boilers and similar apparatus where a liquid is in contact with-its vapor, that the water column is continually condensingthe steam inside it becauseof loss of heat to the surrounding air. There is consequently'a slow current of steam entering thewatercolumn all the time. If this steam containsminute amounts of other gases, such as nitrogen or air, the steam will be condensed and these gases will be left behind until after a period of time the water column will contain a mixture of steam and non-condensible gases and the non-condensible gases may be a very large proportion of the mixture. To a certain extent these noncondensible gases will be carried away by solution in the water formed by condensation of the steam and in this manner will be carried. out of" the bottom of the column back into the boiler again. In many cases, however, and especially with low pressure or poor feed wateror irregular feeding of water tothe' boiler, it has been found that the rate of accumulation of the gases is very much greater than the rate at which they can be carried out; and in many instances it has been observed that these gases constituted such a large proportion of the steam-gas mixture asto make the water column almost cold to the touch for an appreciable distance above the water level. The said gases will be carried to the region directly over the water, and it is'necessary, therefore, to have some device which will skim them, as it were, from just above the water. This invention sets forth just such a device.

By means of a vertically disposed tube I with several holes in it the gases are drawn up' through the tube into a venting device which. permits them to escape to the surrounding atmosphere. The perforated tube running down the interior of the apparatus has some holes above the normal water level condensation trickles down the interior of the perforated tube which leads to the said venting device. Fresh steam then rises in the tube to take the place of the steam condensed. It will be noticed, by reference to the drawings, that this steam is drawn in part, at least, from the region directly over the liquid and so if there is air or non-condensible gases mixed with the steam-directly over the liquid, this air will be drawn upinto the venting device and since it cannot condense and run back into the apparatus again, the air or non-condensible gases will accumulate in the venting device from which they can be discharged.

In this particular embodiment, a thermostatic valve is shown, which will open and permit the non-condensible gases to escape when they have accumulated in suflicient amounts to make the temperature of the valve materially less than the temperature it would have if filled entirely with steam. Should the valve seat leak slightly, the operation would be continuous instead of intermittent and the non-condensible gases would escape together with a small quantity of steam.

It will be observed that a venting device of the character set forth herein can be used in connection with any liquid in contact with its vapor where the vapor contains noncondensible gases and where it is desired to separate the vapor from the non-condensible gases.

I claim:

1. The combination with apparatus responsive to a difference in temperature, a container for liquid of varying level associated with said responsive apparatus having elements both in the liquid and above its normal level, and connections to the container above and below the level of the liquid therein for a condensible gaseous medium; of venting means for eliminating from said container non-condensible gases,and comprising a tube inserted therein and having openings along its length afiording communication at all times with the space above said liquid, and a venting member connected with said tube for releasing non-condensible gases therefrom.

2. The combination with apparatus responsive to a difference in temperature, and a container for liquid of varying level, said container being adapted for connection with "a steam boiler and associated with said re-- sponsive apparatus, the latter having elements both in the liquid and above its normal level; of venting means for eliminating from said container non-condensible gases, and comprising a tube extendlng therein and outwardly therefrom, said tube having openings along'its length affording communication at all times with the space above said liquid, and an automatic thermostatically-operated venting member connected with the outer end of said tube opening to release noncondensible gases and closing upon delivery of steam to said venting means.

3.,The combination with apparatus responsive to a difierence in temperature, and a container for liquid of varying level, said container being adapted for connection with a steam boiler and associated with said responsive apparatus, the latter having elements both in the liquid and above its normal level; of venting means for eliminating from said container non-condensible gases, and comprising a tube extending therein and outwardly therefrom, said tube having openmgs along its length affording communication at all times with the space above said liquid, and a thermostatically controlled valve connected with the outer end of said tube and opening to release non-condensible gases and closing upon delivery of steam to said venting means.

4. The combination with apparatus responsive to a difference in temperature, and a container for liquid of varying level, said container being adapted for connection with a steam boiler and associated with said responsive apparatus, the latter having elements both in the liquid and above its normal level; of venting means for eliminating from said container non-condensible gases, and comprising a tube extending therein and outwardly therefrom, said tube having openings along its length affording communication at all times with the space above said liquid, and an automatic thermostatically-operated venting member with proportionately large radiating surface connected with the outer end of said tube and opening to release non-condensible gases and closing upon delivery of steam to said venting means.

5. The combination with a container for liquid of varying level, a fitting at the bottom thereof and a T at the top for connec tion to a boiler, and means responsive to a difference in temperature located within the container and having elements both in the liquid and above its normal level; of a tube extending through the T into said container and having openings along its length affording communication at all times with the space above said liquid, and a venting valve in communication with the outer end of said tube.

6. In combination: a container for liquid of varying level, a tube mounted therein having openings along its length affording communication at all times with the space above said liquid, and thermostatically controlled means connected with said tube for auto- 10 matically venting non-condensible gases therefrom.

Signed at New York, in the county of New York and State of New York this 13th day of February, A. D. 1925.

, THOMAS s. DERR. 

